CA1097966A - Air burst munitions simulator - Google Patents

Abstract

ABSTRACT

The invention disclosed relates to an improved highly mobile mortar-type launcher. The launcher includes a multiple barrel arrangement wherein the barrels are mounted on a common base and are disposed on the base at suitable angles to each other. Controlled dissemination of a readily dispersible substance in air may be achieved by launching and bursting suitable projectiles containing the sub-stance.

Description

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This invention re]ates to a multi~le-barrclled mortar-type launcher adapte(l for uic in the controlled dissemination in air of a readily disper-sible substance in powder or liquid form.
At prcscni such substancés are delivered in air by (l) air-craft fitted witll spray equil)ment (2~ by ground-burst munitions simulators and (3) by air-burst munitions simulators.
rhe aircraEt fitted spray equipment is very expensive. Additionally, aircra~t dis-lemi~ tion normally requires low-altitude flying with its inherent dangers. l`urthcl, no elcment of surprise is possible, since the aircraft is nolmalLy visiblc For somc time prior to delivery of the training agent.
(round-burst rnunitions simulators invo]ve the emplacement of explosively activated containers in the training area prior to arrival of the troops. Tllis l~roccdurc defea~s any element of surprise. As the troops proceed across the training area, the simulators are detonated to produce ground bursl s~ Ul)on detonation, a powder or liquid is ejected into the air to simulatc c~)losic)n oE grount burst munitions such as mines and shells.
Injury to pcrs~-nn(l due to container fragmentation is a real possibility.
An effective ground-bulst simulator is the subject oE applicant's Canadian patcllt numl)cl ')')7,')6() wlllcll issued on 5 October 1976.
Ai~-burst munitions simulators (ABMS) provide a useful aerial rclcase Or ~ccnlily di;l)crxll)le substances. Whilc the requirement of surprlse is ;atisrie(l by ~l~c locaLion or the launcher outside oE the training area, tlle only launcl~(rs prescntly available are sing]e-fire~ Thus, in order to disseminatc su(~ a substance in air a pluraliLy of single-fire launchers must be indivi(luaLly cmplaced on the ground at difEerent points. It is thus very dilri~ t) I)rovide a dcsire(l pattcrn oE contamination. This limits their uscrulness in the flexible environrnent of a training exerciseO
A suitable air-burst munitions sirnulator is the subject of applicant's co-pending Canadian applicatlon seria] number 218,007 filed 16 January 1975.

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The aforementioned disadvantages may be overcome according to the present invention by providing a mortar-type multiple-barrelled launcher having a range sufficient to achieve surprise, which can launch a group of projectiles cor,taining a readily dispersible substance into -the air in a predetermined location, at sufficiently high altitudes to minimize the danger to ground personnel~
According to one aspect of the invention, an improved mortar-type launcher is provided, said launcher comprising a group of barrels mounted on a common base, said barrels being disposed on said base at suitable angles to each other, the improvement comprising adjustment means for adjusting the angle of elevation of the group of barrels to the horizontal.
In another aspect of the invention, a method for controlled dissemi-nation of a readily dispersible substance in air is contemplated, comprising launching from the ground at suitable angles to each other and to the horizontal, a group of projectiles containing said substance, and bursting said projectiles to release said substance in air in a predetermined pattern and location3 by controlling the launching angle and bursting time of said projectiles.
In the drawings which serve to illustrate a preferred embodiment of the invention:
Figure 1 is a perspective view of the multiple launcher according to the invention, Figure 2 is a side elevation of the novel multiple launcher, and Figure 3 is a side elevation in section illustrating one of the barrels of the novel launcher charged with an air-burst chemical simulator.
The device illustrated comprises a group of five barrels 10 mounted on a common base 120 The barrels 10 are carried by holders 14. The barrels 10 are conveniently fitted into the holders 14 by a telescoping arrangement, for each discard after use. With this in mind, the barrels 10 are constructed of a suitable expendable material, for example, cardboard-or the like, the preferred material being ~" cardboard. Cardboard has the advantage of being particularly inexpensive. An expendable material is used t~o avoid the necessity of decontam-ination procedures following use.

The holders 14 are permanent and are conveniently constructed of a suitable light-weight material, for example, aluminum.

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The barrels 10 are disposed at s~lit:able angles to each other and are mounted radially with respect to the center of the common base 12. The barrels 10 are all disposed in the same plane in a fan-like manne~ covering about 60 of said plane i.e. 30 each side of center. The center barrel lOA is aimed substantially straight ahead, and the two pair of outer barrels lOB and lOC located on either side of the center barrel 10~ are arranged at angles of about 15 to one another. The barrels 10 are inter-connected and rigidly maintained in this configuration by means of supporting gussets 18.
The center barrel 10~ is carried by a central column 13, the outer barrels lOB and lOC being connected to themselves and to the central column, respect-ively, by gussets 18. Connections between holders 1~, the central column 13 and gussets 18 are conveniently effected by welding.
It will be seen particularly from Figure 1 that the group of barrels is rotatably mounted on the common base 12 about a common axis of rotation.
The rotatable mounting is seen to comprise a ball and socket arrangement. A
ball 20 is carried by central column 13 and a socket 22 is conveniently pro-vided in the common base 12. This arrangement provides means for controlling the elevation or aim of the barrels as a group, enabling the group of barrels to be elevated to any angle of inclination to the horizontal within the range of a conventional bi-pod 30 i.e. from about 35 to 65, and rotated through 360.
The bi-pod 30 is provided for adjusting and maintaining the aim or elevation of the group of barrels with respect to the horizontal axis. The supporting base 12 and bi-pod 30 are both conveniently that of a standard `81mm mortar.
More specifically, the angle of elevation of the central column 13, with respect to horizontal, can be adjusted using the bi-pod 30, and the angle of elevation can be monitored using a clinometer 95. The bi-pod 30 and clinometer 95 can also be used to con~rol and monitor the rotation of the outer barrels lOB and lOC about the central axis of the column 13, so the launcher can be set level in this plane as well~ When the elevation of the central column 13 has been set and the rotational attitude of the outer barrels lOB and lOC adjusted to level, the group of five barrels are on the same plane, but the outer barrels lOB and lOC are at angles with the horizontal which differ somewhat from th angle of elevation of the central column 13. The O~/4 ~97~6~;

differences in the angles of elevation between the barrels lOA, lOB and lOC
are considerable and was, during the design phases of the project, considered as a possible problem area relating to burstingaltitude of the projectiles.
Later when the launcher was field tested, it was discovered that the differences in barrel elevation, which were inherent in the system, did not produce signi-ficant variations in the bursting altitude of the projectiles. For example, when the elevation of the center barrel lOA is set at 45, the elevation of barrels lOB and lOC are 42.8 and 35.9, respectively.
Electrical conductors (not shown) run from the base of each of the barrels 10 under covers 26 and into the central column 13 where they are col-lected at a junction 28.
A remotely positioned detonation control system 29 may be electrically connected to the launcher by a multi conductor electrical cable 31 connected to junction 28.
In figure 3, one of the barrels 10 of the launcher is illustrated, in-cluding an ABMS 40 ready for firing. As mentioned above, the ~BMS 40 is the subject of applicant's co-pending Canadian application serial number 218,007, filed January 16, 1975. It is seen to comprise a container 42, conveniently closed with a screw-type cap 44. The container is formed from a light plastic material which is readily shattered by a small explosive bursting charge. A
thin-walled polyethelene container has proven suitable. The screw cap 44 can suitably be formed of plastics material such as polypropylene. A collar 46 is mounted in the base 47 of the container 42. A shoulder 48 is included in the collar to abut against the container base 47, such that a portion of the collar 46 is within the container 42 and a portion is disposed outside of the container. The collar 46 is also conveniently made of polyethelene.
An obturator 50, a dish-like member also formed of polyethelene is mounted flush with the container base 47 and encloses the portion of the collar 46 disposed outside of the container 42. The obturator 50 acts to-gether with a disk 52 to define a confined air space 54. A collar cap 51 is threaded onto the outside portion of the collar 46 after the obturator 50 is - ~ _ 5 _ ~ 7~

located, to maintain positioning. A tirne-delay fuse 56 is providedto set off abursting charge 58 located within the collar 46. Filler discs 60 are provided to allow for different lengths of fuses 56 depending upon the requirements.
The disc 52 is conveniently constructed of 3/4" plywood and is rigidly fixed to the expendable barrel 10, for example, by a fastener 70, and includes a central opening 62 through which an open-ended propellant containing capsule 64 protrudes into air space 54. The open end of capsule 64 is closed by a propellant-retaining diaphram 66 maintained in position by a snap-ring 67.
small charge of black powder 68 is included in the capsule 64. A second ply-wood disc i2 is similarly secured to the expendable barrel 10 for stability purposes.
An electrical fuse element 74 is disposed within the capsule 64 to con-tact the propellant charge 68. Live and ground terminals 76 and 78, respect-ively, are electrically connected by said fuse element 74.
An aluminum base 80 is fixed to the holder 14 conveniently by welding.
An electrical contact housing 82 is threaded `into a central opening 84 in said base 80. The housing 82 includes a teflon ~ insulator 86 which carries an electrical terminal 88. The insulator 86 is mechanically biased by a compressed coil spring means 90, such that terminal 88 is maintained in contact with ter-minal 76. An electrical conductor 92 connected to terminal 88 carries an elec-trical current from the detonation control unit 29 through multi-conductor electrical cable 31 to ignite the propellant charge 68.
In operation, five projectiles containing a readily dispersible sub-stance are launched simultaneously from a position upwind of the training area.
The projectiles are burst in air in a predetermined pattern and location and the cloud pattern so formed then drifts over the training area where it settles to the ground.
Specifically the burst pattern or lateral spread of bursts depends upon the relative launch angles i.e. the relative angles of the barrels. In this case, the barrels are co-planar and their relative angles fixed. Ilowever, it will be appreciated that means could be provided for adjusting these angles.

...l6 By arranging and fixing the disposition of the barrels in this manner, a predetermined pattern of the substance in air may be achieved. For example, with the centre barrel lOA aimed straight ahead and the two pairs of outer barrels lOB and lOC co-planar and displaced from the center barrel lOA by about 15 and 30, respectively,a lateral spread or cloud of about 200 meters in length results.
The burst location is determined by burst height or altitude and down-range distance i.e. horizontal range. These factors are controlled by varying the angle of elevation of the central column 13, the length of the time delay fuze 56, and the amount of propellant 68. For example, if the amount of propellant and the length of the delay fuze is constant from firing to firing, the horizontal or down range travel of the projectile increases as the angle of elevation is increased from 0 to 45 . At angles of elevation greater than 45 , the down range or horizontal travel begins to decrease until at an elevation of 90 there would theoretically be no down range travel at all.
Conventional tirne-delay fuses and a blasting cap are used to detonate the burster charge. By selecting an appropriate fuse length, the time of bursting may be controlled. A suitable bursting charge such as tetrytol ~ 70l30 is used. The containers are conveniently launched with a suitable amount of a black powder charge detonated electrically from a remote location, More specifically, the projectiles are launched at flxed angles to each other and as a group of projectiles are launched in the same plane.
The projectiles all include the same length of time-delay fuse. By selecting a la~mch angle, fuse length and amount of charge, the lateral spread of sub-stance i.e. the pattern; the burst height and the horizontal range i.e.
location; may be controlled. Launch angles of about 40 to 45 were found to provide the most effective horizontal range, Fuse lengths of about 1.91 to about 3.18cm were found to provide sufficient time delays. A charge of 25.0g black powder was found ~o enable suitable burst height.
The propellant charge 68 is ignited by the electrical fuze wire 74 which is vaporized when it is connected to a low voltage, high current elec-trical power source such as an automotive battery. The control unit 29 is basically capable of providing the following functions:

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a. Providing a reliab]e electrical isolation between the power source and the launcher during the loading phase.
b. Checking the loaded launcher to en~ure that the fuze wires 74 are intact and properly connected to the firing lines of the launching system in preparation for firing.
c. Applying the electrical power to the fuze wires 74, in order to heat and vaporize them, which results in the ignition of the propellant charges.
The launcher control unit is capable of firing the ABMS units separately, in selected groups, or all barrels simultaneously.
Trials have been carried out to establish the reliability of the 5-barrel launcher for projection of the air-burst munitions simulator ABMS , ~a~er-charged, when fired from the ground. In these trials, the ABMS was charged with 3kg water dyed with crodecen scarlet. The propellant charges consis~ed of 25~g FFF gunpowder.
The layout consisted of two lines of photo markers spaced 15m apart down range from the launcher position. One camera was located directly to the rear of the launcher at approximately 100m to record the lateral dis~ance between bursts and the altitude of the bursts. A second camera was located approximately 150m across range from the middle marker to obtain photographic records of the down range flight distance of the simulators. Radio communica-tion was provided between these positions and the firing point. The launcher was functioned electrically by land line.
_ OCEDURE
Before each firing the electrical circuit was checked for continuity.
Before loading, the power supply to the launcher was interrupted by disconnec-ting the firing line, switching off the firing box and removing the control key, to ensure that there would be no current to function the launcher during load-ing. The required elevation was then set by means of the 81mm mortar clino-meeer prior to loading the ABMS into the launcher. Each of the five launcher assemblies was loaded with an ABMS, armed with the propellant charge and then seated in the launcher barrel.

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The firing line was reconnected to the firing box, the on/off, key replaced and power to the launcher was restored~ The launcher was again tested for continuity to each launcher assembly, and after a five second countdown sent by radio, the launcher was fired. Both cameras were operated manually by photographic personnel and recorded heights of burst, distance between bursts and flights down range respectively.
Twelve firings were carried out in the meteorological conditions sum-marized in Table l; details of launcher elevation, fuze length and propellant weight are given in Table 2. No misfires occurred and in each case the five simulators were launched simultaneously. One launcher assembly failed in shot 2 due to separation of the wooden base from the cardboard tube. All simulators were stable in flight.
The mean performance of the system in terms of lateral spread of the bursts, burst height and downrange distance to burst against launcher elevation and fuze length for a 25g propellant charge is summarized in Table 3.
Details of burst location i.e. lateral distance between bursts, heights of burst and mean downrange distances of burst for each shot as determined from the photographic records are given in Table 4. A maximum horizontal range of 123m and a average height of burst of 47.5m was achieved.

...l9 r~ 6 _ 9 _ TABLE 1: METEOROLOGICAL CONDJTIONS
__ DATE/TIME: 16 July 1975, lOqO ~ 0 hrs.
WltlD YELOCITY AND TEMPERATURES

Altitude D~r T ~n/hr ¦ ~ir T~np (C) _.
. 15.2m 220 35 1 20 . 45.7m 225 4Z 1 20 : 91.4m 220 40 , _. ~ _ Air T~llp. at 2m = 23 C
: R/H = 47%

. . . /10 TABLE 2: F TRINC 5CIIEDUIJE

Shot Saf~ty I'rol~el 1 ant ~o. Elevation Fuze Charq~
~ --_ .
. 1 40 1.91 cm 25.0 gram . ........ _ 2 40 1.91 cm 2s. n "

. 3 40 2.54 cm 25.0 "
._ . . .
4 40 2.54 cnn 25. n . . ....
4oo 3.1~3 cnl 25.n "
,_ __ _ 6 40 3.18 cnn 25. n 7 45 1.9I cm 25.0 45 1.91 cm 25.0 "

45 2.54 cm 25.0 "

45 2.54 cm Z S .0 11 45 3.18 cm 25.0 . - . _ 12 45 3.18 cm 25.0 . ~ . / 1 1 .. . _ . _ .. -- _ _ _ . _ _ . _ _ . . . ~ . _ _ .. _ ~ _ . . .. .. _ _ . _, . _ . _ ~

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TABLE 3: I`IE~\N P~RFORMANCE WII~I 25~ Ol'l~l.LAN'r CIIARGE
_ _ _ _ __ _ El evation Fu~eLateral ~urst L'~lnrdrl(1e (deg) (cnl) Spread (m) lleight (m) n1st ( l . 9l 170 44 7 - . _ ___ 2.54200 45 l _ _ ~

3.18 216 34 116 _ __ _ __ I__--1. 91 1~6 65 7~3 2. 54 1~8 - 5~ 67 _ _ ~__ 3 ~ 13 ~ l nn . . ./12 ~A~L~

Shot Lateral Dlstance Between ~eights of Burst Do;nlran(le Bursts (m) (m) Distance llo. 1-2 2-3 4-5 Mean 2 3 4 5 'lean Mean ._~ _ _ _ 1 a 47 4 14 8 4 5 a 4 9 524 3 43 47 B0 2 41 38 35 46 40 42 42 3046 43 4~ 75 . . _ ;.
3 96b~~ 1û5b -- 50 48 b 55 b 30 44 111 _ _ _ __ ___ _ .

4 49 S5 37 60 50 48 a5 7325 39 a69~3 _ _ _ __ __ a 42 64 50 52 a 42 353B 13 32I 14 1- ------~ ~------~
6 51 61 55 a 56 39 28 40 41 a 37118 _ __ . __ ~_ __ __ ~ I _ _.
8 52 54 47 36 4750 82 81 77 58 7n87 _ ~. ._ _ _ __ 9 20 44 3859 4038 16 60 62 49 a561 . . _ 11 a 41 4073 51 a 12 64 57 21 3892 _ _ _ 12 47 62 6018 4734 Sl 75 SB 17 4712B
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a. Burst not in photo.
b~ 2 ar-d 4 d;d not burst.
Sirnulators numbered from L to R look;ng downran~e , I] 3 ` - 13 _ ~ ~97~6~
.
The launcller utilizes components from the 81mm British Mortar, which is found within the Canadian ~orces and due to its si~e is highly mobile which gives it flexibility in deployment and is small enough to provide a good degree of surprise as it can easily be camouflaged. It provides a controlled means of dissemination where and when it is required. Due to its simplicity it is easy to train user personnel in a minimum period of time.
It will be appreciated that the invention has been described in re-lation to the dissemination of a readily dispersible substance in air. However, it will be apparent to those skilled in the art that the present invention may be used for purposes other than those specifically described herein, for example, ~or the placement of charges at a specified location on glaciers to initiate avalanches, and in the dissemination of insecticides over inaccessible forest areas, without departing from the spirit or central characteristics of this invention. Thus, the specific embodiment described in herein is considered in all respects as illustrative and by no means restrictive.

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Claims (18)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a mortar-type launcher including a group of barrels mounted on a common base, said barrels being disposed on said base at suitable angles to each other, the improvement comprising providing adjustment means for adjust-ing the angle of elevation of the group of barrels to the horizontal.

2. A mortar type launcher according to claim 1, wherein said barrels are mounted radially with respect to said common base.

3. A mortar-type launcher according to claim 2, wherein said adjustment means comprises ball and socket means for adjusting said group of barrels along a common axis of rotation.

4. A mortar-type launcher according to claim 3, wherein said group of barrels are all disposed in the same plane.

5. A mortar-type launcher according to claim 4, wherein said barrels are arranged in fan-like manner covering about 60° of said plane.

6. A mortar-type launcher according to claim 5, wherein said barrels number five and are arranged at angles of about 15° to one another.

7. A mortar-type launcher according to claim 6, including means for aiming said group of barrels.

8. A mortar-type launcher according to claim 1, 3 or 7, wherein said barrels are of a suitable expendable material.

9. A method for controlled dissemination of a readily dispersible substance in air, comprising launching from the ground at suitable angles to each other and to the horizontal, a group of projectiles containing said substance, and bursting said projectiles to release said substance in air in a predetermined pattern and location, by controlling the launching angle and bursting time of said projectiles.

10. A method according to claim 9, wherein said projectiles are launched simultaneously.

11. A method according to claim 10, wherein said projectiles are con trolled to burst simultaneously.

12. A method according to claim 11, wherein the amount of propellant charge is controlled.

13. A method according to claim 12, wherein said group of projectiles are launched in the same plane.

14. A method according to claim 13, wherein said group of projectiles are launched at an angle of about 35-45° to the horizontal.

15. A method according to claim 9, wherein the bursting time of said projectiles is controlled by varying the fuse length, and wherein the fuse length is about 1.91 to 3.18cm.

16. A method according to claim 15, wherein said group of projectiles is launched at an angle of about 40° to the horizontal.

17. A method according to claim 15, wherein said group of projectiles is launched at an angle of about 45° to the horizontal.

18. A method according to claim 16 or 17, wherein said group of projec-tiles numbers five and wherein the launch angles between said projectiles in the same plane are about 15°.